The rapid and effective repair of bone defects caused by injury, disease, wounds, or surgery is a goal of orthopedic surgery. Toward this end, a number of bone implants have been used or proposed for use in the repair of bone defects including spinal stenosis. The biological, physical, and mechanical properties of the bone implants are among the major factors influencing their suitability and performance in various orthopedic applications.
Spinal stenosis is the narrowing of the spinal canal, which can lead to an impingement on the spinal cord and various nerves resulting in symptoms of moderate to extreme pain. Bone implants are used to alleviate symptoms associated with spinal stenosis. Bone implants are also used to repair bone that has been damaged by disease, trauma, or surgery. In some types of spinal fusion, for example, bone implants are used to replace the cushioning disc material between the vertebrae or to repair a degenerative facet joint.
During certain spinal corrective procedures, such as for example, alleviating spinal stenosis pain and/or a spinal fusion procedure, bone implants are positioned in an interspinous process space. The interspinous process bone implants attempt to lessen pain caused by spinal stenosis by redirecting pressure away from the foramina. Interspinous process bone implants can also be used to facilitate bone remodeling and new bone growth, and integration of the bone implant (e.g., allograft) into host bone. However, interspinous process implants carry several inherent drawbacks. Exemplary disadvantages of interspinous process bone implants include difficulty mechanically fixing the implant to the spinous processes; erosion of adjacent bone; and fracture of the spinous process due to the relatively thin and weak nature of the spinous processes.
The present disclosure offers several advantages over interspinous process implants to lessen pain caused by spinal stenosis and/or maintain an intervertebral space during fusion of adjacent vertebrae.